Downstep (phonetics)

In phonetics, downstep is a phonemic or phonetic downward shift of tone between the syllables or words of a tonal language. It is best known in the tonal languages of West Africa, but the pitch accent of Japanese (a non-tonal language) is quite similar to downstep in Africa. Downstep contrasts with the much rarer upstep. The symbol for downstep in the International Phonetic Alphabet is a superscript down arrow, ^↓, which is not yet supported by Unicode. It is common to see a superscript exclamation mark, ^!, used instead.

Phonetic downstep may occur between sequences of the same phonemic tone. For example, when two mid tones occur together in Twi, the second is at a lower pitch than the first. Thus downshift plays a vital role in downdrift and tone terracing.

Phonemic downstep may occur when a low tone is elided, or occurs as a floating tone, and leaves a following tone at a lower level than it would otherwise be. An example occurs in Bambara. In this language, the definite article is a floating low tone. With a noun in isolation, it docks to the preceding vowel, turning a high tone into a falling tone:

/bá/	river
/bâ/	the river

However, when it occurs between two high tones, it downsteps the following tone:

it's not a river
	it's not the river

Japanese pitch accent is similar. About 80% of Japanese words have an evenly rising pitch, something like French, which carries over onto following unstressed grammatical particles. However, a word may have a drop in pitch between morae, or before the grammatical particle. An example is

/ka↓ki/	[kákì]	oyster
/kaki↓/	[kàkí]	fence
/kaki/	[kàkí]	persimmon

In isolation like this, the first word has a high-low pitch, whereas the second and third are homonyms with a low-high pitch. (The first syllable is only low when the word is said in isolation.) However, all three are distinct when followed by the so-called "subject" particle ga:

/ka↓kiga/	[kákìgà]	oyster
/kaki↓ga/	[kàkígà]	fence
/kakiga/	[kàkīgá]	persimmon